Technical Field
This disclosure relates to memory devices, and more particularly in at least one embodiment to post-packaging repair of a memory device.
Description of Related Technology
Memory cells of memory devices such as dynamic random access memories (DRAMs), static RAMs (SRAMs), flash memories, or the like may experience defects leading to errors and/or failures. Memory cells can also fail to operate with sufficient speed, short enough latencies, or the like. In some cases, memory cells may be identified as defective (hereinafter “defective memory cells”) after the memory device (e.g., a memory chip) has been packaged, such as in cases where the memory cells were not detective before the packaging process. Examples of packaging include, but are not limited to, encapsulation by epoxy, ceramic packages, metal/glass packages, and the like. After a memory device has been packaged, the memory device may be tested to identify defective memory cells. Addresses mapped (e.g., assigned) to defective memory cells may be remapped (e.g., reassigned) to functional or otherwise more desirable memory cells (e.g., memory cells that have not been identified as defective) so that the memory device may still be effective or meet a desired operational characteristic.
Non-volatile memory (e.g., fuses or antifuses) may be programmed to store data corresponding to one or more addresses mapped to defective memory cells. An antifuse has a high resistance in its initial state. An antifuse may permanently create an electrically conductive path when a relatively high voltage is applied across the antifuse. An antifuse may have a structure similar to that of a capacitor, i.e., two conductive electrical terminals are separated by a dielectric material. To create an electrically conductive path, a relatively high voltage is applied across the terminals, breaking down the interposed dielectric material and forming a conductive link between the antifuse terminals. Creating a conductive path through an antifuse is referred to as “blowing an antifuse.”
Certain protocols exist for performing post package repair. Such existing protocols have various drawbacks. Accordingly, a need exists to improve post package repair.